A nonsense mutation in the optic atrophy 3 gene (OPA3) causes dilated cardiomyopathy in Red Holstein cattle

Cardiomyopathies are severe degenerative disorders of the myocardium that lead to heart failure. During the last three decades bovine dilated cardiomyopathy (BDCMP) was observed worldwide in cattle of Holstein-Friesian origin. In the Swiss cattle population BDCMP affects Fleckvieh and Red Holstein breeds. The heart of affected animals is enlarged due to dilation of both ventricles. Clinical signs are caused by systolic dysfunction and affected individuals die as a result of severe heart insufficiency. BDCMP follows an autosomal recessive pattern of inheritance and the disease-causing locus was mapped to bovine chromosome 18 (BTA18). In the present study we describe the successful identification of the causative mutation in the OPA3 gene located on BTA18 that was previously reported to cause 3-methylglutaconic aciduria type III in Iraqi-Jewish patients. We demonstrated conclusive genetic and functional evidence that the nonsense mutation c.343C>T in the bovine OPA3 gene causes the late-onset dilated cardiomyopathy in Red Holstein cattle.

Effects of different types of solid feeds on health status and performance of Swiss veal calves. I. Basic feeding with milk by-products

The objective of this study was to identify a suitable alternative to the current practice of complementing the feeding of milk by-products with straw. The influence of 5 different types of solid feeds on health and performance of Swiss veal calves was investigated in 2 production cycles of 200 veal calves each with a mean initial age of 40 days (d). The calves were housed in groups of 40 in stalls with outside pen. Liquid feeding consisted of a milk by-product combined with an additional skim milk powder ad libitum. Groups were assigned to 1 of the 5 following experimental solid feeds provided ad libitum: mix (composition: soy flakes, corn, barley, wheat, oat, barley middling, plant oil, molasses), whole plant corn pellets, corn silage, hay, and wheat straw as control. Daily dry matter intake per calf averaged 2.25 kg of the liquid food, 0.16 kg of straw, 0.33 kg of mix, 0.47 kg of corn silage, 0.38 kg of corn pellets, and 0.39 kg of hay. No significant differences (P > 0.05) among groups were found in calf losses that amounted to 4.8 % (68 % because of gastrointestinal disorders). Four percent of the calves were slaughtered prematurely. Daily doses of antibiotics were higher in the mix (36.9 d, P < 0.01) and in the corn silage groups (35 d, P < 0.01) compared to control. Compared to the 4 other groups, calves of the straw group showed the highest prevalence of abnormal ruminal content (73 %, P < 0.05), of abnormal ruminal papillae (42 %, P < 0.05), of abomasal fundic lesions (13.5 %, P < 0.1), and the lowest number of chewing movements per bolus (45, P < 0.05). The hemoglobin concentration averaged 85 g/l at the beginning and 99 g/l at the end of the fattening period with no significant differences among groups (P > 0.1). The duration of the fattening period averaged 114 d, slaughter age 157 d, and carcass weight 122 kg. The average daily weight gain (ADG) was highest in the control group straw (1.35 kg), and lowest in the hay group (1.22 kg, P < 0.01). The number of carcasses classified as C, H, and T (very high to medium quality) was lower in the hay group compared to straw (P < 0.01). No significant differences between groups were found in meat color (P > 0.1): 73 % of the carcasses were assessed as pale (267/364), 18 % as pink (66/364), and 9 % (31/364) as red. The results reveal that whole-plant corn pellets are most consistent with an optimal result combining the calves' health and fattening performance. Therefore, it can be recommended as an additional solid feed for veal calves under Swiss conditions.